Allyson May on wed 6 may 09
ClayArt Folks
I have been working on some functional pieces in ^6 porcelain which I =3D
decorate with black slip. I carve thru the slip to reveal the claybody =3D
at the leather hard stage. I really like the black slip I am using. =3D
Its very black, applies well and has no problems with fit on my clay. =3D
The problem is that I can't seem to find a clear glaze to go over it. I =
=3D
have tried several clear glazes and have problems mostly with pin =3D
holing. I have also had the clear seem to over flux the slip and cause =3D
the carving to be very blurred or disappear altogether. I have =3D
experimented with different slips and engobes but I don't get the deep, =3D
true black that I want. Can some of you glaze gurus give me a hand? =3D
Since I don't use the slip on the food surfaces of my work can I =3D
reformulate my slip to be vitreous at ^6? I'm guessing that I would =3D
need to add more frit or maybe neph sy? How much should I start with? =3D
With this alternative I would hope for more satin and less matt. I'm =3D
willing to test but really need some guidance on where to start. I =3D
would also like to know if anyone has a tried and true black slip and =3D
clear glaze combo on ^6 porcelain. If I have to I will switch to a new =3D
slip if I can solve my problems and still get a very black result. =3D20
I slip decorate at leather hard, bisque on slow bisque to ^04 and make =3D
sure my bisque is clean prior to glazing by dipping.
Here is the slip I'm using:
Don's Engobe Base
#6 tile clay 25
EPK 25
OM4 ball clay 25
Frit 3124 15
Nepheline syenite 10
Add: Mason stain #6600 10%
Clear glazes I have tried:
M^6G Clear Glossy Liner: pinholes
Don's Clear: pinholes
VC Transparent: pinholes and hardpans so much it isn't worth the trouble
Clear Satin Matt: over flux and obscures the carving.
Any help would be appreciated. I'm am learning more and more about =3D
glazes but still feel like a neophyte when it comes to this.
Peace,
Allyson May
gayle bair on wed 6 may 09
Allyson try thinning your clear glaze.
Mine is more a consistency of whole milk rather than a cream.
Test with any of your clear glazes and I think you will see improvement.
It worked for me.
I've used Amaco black and Seattle Pottery black slip but mostly make
my own as I can use whatever claybody I'm using to ensure fit.
Oh one more tip..... thin down your slip don't use it real thick.
Best regards,
Gayle Bair
Tucson AZ
Bainbridge Island WA
gayle@claybair.com
www.claybair.com
On May 6, 2009, at 6:14 AM, Allyson May wrote:
> ClayArt Folks
>
> I have been working on some functional pieces in ^6 porcelain which
> I decorate with black slip. I carve thru the slip to reveal the
> claybody at the leather hard stage. I really like the black slip I
> am using. Its very black, applies well and has no problems with fit
> on my clay. The problem is that I can't seem to find a clear glaze
> to go over it. I have tried several clear glazes and have problems
> mostly with pin holing. I have also had the clear seem to over flux
> the slip and cause the carving to be very blurred or disappear
> altogether. I have experimented with different slips and engobes
> but I don't get the deep, true black that I want. Can some of you
> glaze gurus give me a hand? Since I don't use the slip on the food
> surfaces of my work can I reformulate my slip to be vitreous at ^6?
> I'm guessing that I would need to add more frit or maybe neph sy?
> How much should I start with? With this alternative I would hope
> for more satin and less matt. I'm willing to test but really need
> some guidance on where to start. I would also like to know if
> anyone has a tried and true black slip and clear glaze combo on ^6
> porcelain. If I have to I will switch to a new slip if I can solve
> my problems and still get a very black result.
> I slip decorate at leather hard, bisque on slow bisque to ^04 and
> make sure my bisque is clean prior to glazing by dipping.
> Here is the slip I'm using:
>
> Don's Engobe Base
>
> #6 tile clay 25
> EPK 25
> OM4 ball clay 25
> Frit 3124 15
> Nepheline syenite 10
>
> Add: Mason stain #6600 10%
>
> Clear glazes I have tried:
> M^6G Clear Glossy Liner: pinholes
> Don's Clear: pinholes
> VC Transparent: pinholes and hardpans so much it isn't worth the
> trouble
> Clear Satin Matt: over flux and obscures the carving.
> Any help would be appreciated. I'm am learning more and more about
> glazes but still feel like a neophyte when it comes to this.
>
> Peace,
> Allyson May
Ron Roy on wed 6 may 09
Hi Allyson,
I just compared your black slip to a dark cone 6 clay body (another parlor
trick) and it may be that it's over fluxed for cone 6. It's easy to compare
clays using the molecular formula - it's how I redo clay bodies when
materials change or become unavailable.
If that slip is over fluxed then that would explain the pinholing.
Try the same slip (1000 grams) with only 5% frit and no frit. - maybe try a
version with 10% frit as well - that will certainly prove the point if that
is the problem.
RR
On Wed, May 6, 2009 at 9:14 AM, Allyson May wrote:
> ClayArt Folks
>
> I have been working on some functional pieces in ^6 porcelain which I
> decorate with black slip. I carve thru the slip to reveal the claybody a=
t
> the leather hard stage. I really like the black slip I am using. Its ve=
ry
> black, applies well and has no problems with fit on my clay. The problem=
is
> that I can't seem to find a clear glaze to go over it. I have tried seve=
ral
> clear glazes and have problems mostly with pin holing. I have also had t=
he
> clear seem to over flux the slip and cause the carving to be very blurred=
or
> disappear altogether. I have experimented with different slips and engob=
es
> but I don't get the deep, true black that I want. Can some of you glaze
> gurus give me a hand? Since I don't use the slip on the food surfaces of=
my
> work can I reformulate my slip to be vitreous at ^6? I'm guessing that I
> would need to add more frit or maybe neph sy? How much should I start wi=
th?
> With this alternative I would hope for more satin and less matt. I'm
> willing to test but really need some guidance on where to start. I would
> also like to know if anyone has a tried and true black slip and clear gla=
ze
> combo on ^6 porcelain. If I have to I will switch to a new slip if I can
> solve my problems and still get a very black result.
> I slip decorate at leather hard, bisque on slow bisque to ^04 and make su=
re
> my bisque is clean prior to glazing by dipping.
> Here is the slip I'm using:
>
> Don's Engobe Base
>
> #6 tile clay 25
> EPK 25
> OM4 ball clay 25
> Frit 3124 15
> Nepheline syenite 10
>
> Add: Mason stain #6600 10%
>
> Clear glazes I have tried:
> M^6G Clear Glossy Liner: pinholes
> Don's Clear: pinholes
> VC Transparent: pinholes and hardpans so much it isn't worth the trouble
> Clear Satin Matt: over flux and obscures the carving.
> Any help would be appreciated. I'm am learning more and more about glaze=
s
> but still feel like a neophyte when it comes to this.
>
> Peace,
> Allyson May
>
--
Ron Roy
15084 Little Lake Road
Brighton, Ontario, Canada
K0K 1H0
Des & Jan Howard on thu 7 may 09
Allyson
My post 0f 19 April,"Re: making slip for slip trailing"
mentions the black slip we make for spraying, brushing
or trailing. ( It was mentioned add ~10% vol. CMC mix,
WRONG, 50% vol. CMC mix addition, this makes a very
tough coat pre-biscuit.)*
I know you want a clear glaze over the slip. If your C6
porcelain is sufficiently vitreous it might only need
slightly extra flux, in the slip form, to counteract
the refractory tendency of the stain.
By using a higher pressure with the spray gun the
coating can be applied & if the texture becomes
lessened during the process ease off on the trigger &
use the air blast to move the glug out of the finer spots.
Have a look at the black bowls in May & March.
http://www.luepottery.hwy.com.au/showroom.htm
Des
* CMC mix - 90 gm CMC gum, 1200 ml hot water, disperse
gum. Add 4800 ml cold water, mix with column stirrer.
Makes 3 x 2L juice bottles.
Allyson May wrote:
> I have been working on some functional pieces
in ^6 porcelain which I decorate with black slip.
I carve thru the slip to reveal the claybody at
the leather hard stage. I really like the black slip
I am using. Its very black, applies well and has no
problems with fit on my clay. The problem is that
I can't seem to find a clear glaze to go over it.
I have tried several clear glazes and have problems
mostly with pin holing. I have also had the clear
seem to over flux the slip and cause the carving
to be very blurred or disappear altogether.
I have experimented with different slips and
engobes but I don't get the deep, true black
that I want.
--
Des & Jan Howard
Lue Pottery
Lue NSW
Australia
2850
02 6373 6419
www.luepottery.hwy.com.au
-32.656072 149.840624
MudFire - Luba & Erik on thu 7 may 09
Dear Allyson,
Here's a ^6 clear glaze we've used at MudFire for 7 years. Not a single =
=3D
pit on any of the 16 claybodies in use at the studio. Also takes msot =3D
mason stains very well (up to 10%). All but the greens of course...the =3D
zinc in this baby turns all greens brown ;-)
Good luck
Luba
Super Clear 100g=3D20
Whiting 9.38=3D20
Frit 3195 29.88=3D20
G-200 Feldspar 8.15=3D20
F-4 Feldspar 19.75=3D20
EPK 8.15=3D20
Flint 22.22=3D20
bentonite 2.47=3D20
MudFire Clayworks & Gallery
Open Studio * Workshops * Exhibits
175 Laredo Dr, Decatur, GA 30030
404-377-8033
www.mudfire.com
| |
|
